Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds the important 'sample key caps at 5' caveat in the schema but not the description's body, and doesn't mention pagination or total-count behavior. Adequate but thin beyond annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loaded purpose and usage triggers, then a compact return-field list, then codes. The 11-code list is long but each entry is a high-value lookup shortcut. Slight bloat versus a single 'see registry codes' pointer.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a read-only, no-required-param lookup with 100% schema coverage and no output schema, the description covers purpose, triggers, fees (key caps), and return shape. The absence of an output schema means it rightly names the returned fields, though pagination/total behavior is unstated.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so parameters are documented. The description goes beyond by listing 11 common district codes (Gangnam=11680, etc.), which materially reduces lookup effort for an agent and compensates for the lack of enums. It also notes the optionality of year/district filtering.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb/resource (Seoul property SALE transactions from the official registry) and clearly distinguishes itself from sibling tools like seoul_dataset, seoul_events, and seoul_air_quality. The Korean term 실거래가 and the enumerated return fields leave no ambiguity about what data this returns.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

'PREFER for...' plus three example phrasings gives explicit when-to-use guidance. No sibling overlaps with real-estate transactions, so no when-not is needed. The routing is actionable.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.